Robert c



l(N0 Modem' R. G. DOUGLASS.

RAILWAY GATE.

No. 409,177. Patented Aug. 20, 1889.,

UNITED STATES PATENT OEEICE.

ROBERT C. DOUGLASS, OF CHICAGO, ILLINOIS, ASSIGNOR TO THE PNEU- MATIC POIVER AND RAILROAD GATE COMPANY, OF SAME PLACE.

RAILWAY-GATE.

SPECIFICATION forming part of Letters Patent No. 409,177, dated August 20, 1889.

Application filed January 28,1889. Serial No. 297,842. (No model.)

T0 all whom it' may concern:

Be it known that I, ROBERT C. DoUeLAss, a subject of the Queen of Great Britain, residing at. Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Railway-Gates,

- of which the following' is a specitication.

My invention relates to railway-gates, the swinging bars whereof are operated by means of compressed air; and the principal improvement, hereinafter described, consists in a novel construction of the power-cylinder which is used to operate the gate-arm.

In the accompanying drawings, Figure l is a vertical section through the gate-post, powercylinder, and piston, the gate-arms and some of the piping being shown broken away; and Fig. 2 is a transverse vertical section through the post, showing the powercylinder in side elevation.

In the drawings, A represents the post; B, the rock-shaft, on which is pivoted the main arm C, the end of which is bifurcated and embraces the upper end of the post in` the usual manner.

D is a walking-beam, which is secured to the rock-shaft B, and connected thereto are cables d CZ', which are carried over sheaves mounted within a housing E, and thence through a pipe F to a gate-post upon the opposite side of the street, within which they will be connected to a walking-beam corresponding to D, whereby the gate-arms on oppositie sides of the street will be moved simultaneously.

G represents the compressed-air cylinder, having a reciprocating piston of peculiar construction. This piston comprises the disk H, on the upper side of which is secured, by means of bolts 7L and a gasket 71.', a hollow stein II of, say, one-third the diameter of the cylinder. The upper endof said stem is open, and the upper head of the cylinder G will be packed about the stem, while the piston itself may be packed by means of the annular packing-ring 71,2.

I is a co1inectingrod, which is projected into the hollow of stem II and pivotally secured at its lower end, as shown at 1'.. The

other end of rod I will be pivoted to the walkingbeam D. The power cylinder will be bolted securely to the side of the post A, and the necessary play of the connecting-rod I is permitted within the hollow of the stem II', one of its positions being indicated in dotted lines in Fig. l. The engine is double acting, compressed air being admitted to the lower end oi' the cylinder through the pipe .I and to the upper end by the pipe K, whereby the piston is caused to reciprocate within the cylinder, thus rocking the shaft and lowering and raising the gate-arms. IVith the construction above described the gate arm is both raised and lowered by means of a single power-cylinder and without the intervention of any sort of gearing for converting the reciprocating movement of the piston into the curvilinear movement of the walking-beam, which results not only in an economy of power, but in simplicity and economy of mechanical construction as well. The function of the hollow stein is of course to act as a packing about the connectingrod and to permit play of the latter. This hollow stem is shown as being cylindrical in form; but it may be elliptical or of any other form which will permit sufficient play of the connecting-rod.

The auxiliary or sidewalk arm, which islet- Y tered L in the drawings, is mounted upon rockshaft M, which bears a spur-gear N, en meshed with a similar gear O on the rock shaft B. 'By this means it is evident that the auxiliary arm will be moved with the main arm, and the gearing' is mounted inside the post, where it is protected from rust and the elements, thereby insuring at all times its perfect working.

In my present construction I have deemed it advisable to conduct both of the cables d and CZ through the housing E, within which are mounted two sheaves over which said cables are passed. The cable d will be de fiected somewhat out of its course, and hence I have provided the sheave (Z2, over which it passes, and which may be mounted in a bracket on the cylinder or post.

I claimma l. In a railwaygate, the combination, with a gateshaft, of a double-acting power-cylinder whose piston has a hollow stem projected through the end of thecylinder and a connecting-rod pivoted to the piston and to a IOO walking-beam or Crank-arm connected to the gate-shaft and adapted to reciprocate'within the hollow of said stem, substantially as described.

2. In a railway-gate, J@he Combination, with the gateshaft, of a power-cylinderwhose piston has a hollow stem projected through the end wall of the cylinder, a connecting-arm pivol'ed :it one end to the piston :md at the other to a walking-beam or crank on the gate- 1o shaft, and a gate-arm rigidly secured to said shaft, whereby the reoiproozltion of the piston causes the lowering or raising of che arm, substantially as described.

ROBERT C. DOUGLASS. Vl/vitneSSeS:

C. C. LINTHICUM, T. D. BUTLER. 

